I guess we have all had a parcel delivered to our home marked ‘fragile’; meaning that care must be taken because, if the item contained within is broken, it will be in a worse state. But what is the opposite of fragile? Some would say ‘robust’, but the meaning is more along the lines of ‘being difficult to break’. Nassim Taleb points out, in his fascinating book ‘Antifragile’,that there seems to be no word in English to describe the opposite of fragile: i.e. that when broken, the item is improved or gets stronger.